FILE - In this Nov. 4, 2010, file photo, Philadelphia Flyers' Jody Shelley, left, and New York Rangers' Derek Boogaard fight during an NHL hockey game in Philadelphia. Researchers at Boston University say it's important not to over-interpret results from a study of former NHL enforcer Derek Boogaard's brain that show early signs of a neurodegenerative disease linked to repeated brain trauma.THE CANADIAN PRESS/AP, Matt Slocum

2011-12-06 09:59:00

TORONTO - The discovery that former NHL enforcer Derek Boogaard's brain shows signs of a neurodegenerative disease linked to repeated head trauma is further evidence that a major cultural shift in the game is needed to protect players' health, a brain injury expert says.

"I think the Boogaard case makes it more urgent for organized hockey to take additional steps to reduce hits to the head, and fighting is one of the recognized causes of hits to the head," said Toronto neurosurgeon Dr. Charles Tator.

"My view is the role of the enforcer should be eliminated and no young person should aspire to get into the NHL by assuming the role of an enforcer," Tator, founder of the brain-injury prevention organization ThinkFirst Canada, said Tuesday.

Boogaard was 28 when he died in May of an accidental overdose of alcohol and the painkiller oxycodone. His family donated his brain to a Boston University research centre for post-mortem examination and requested that the diagnosis be made public.

Researchers found clear evidence of chronic traumatic encephalopathy, or CTE, in the brain of the NHL tough guy, who reportedly got into fisticuffs more than 60 times during 277 regular-season games. In his career in the minors, he reportedly dropped the gloves more than 100 times, according to a university report.

CTE, which can only be diagnosed by examining brain tissue after a person's death, has been linked to a host of mood and behavioural changes, including depression, memory problems and aggression. In later stages, the progressively destructive disease can result in severe dementia.

But Dr. Robert Cantu, co-director of the Center for the Study of Traumatic Encephalopathy, said his group's findings should not be overinterpreted.

"Based on the small sample of enforcers we have studied, it is possible that frequently engaging in fist fights as a hockey player may put one at increased risk for this degenerative brain disease," he said in a release.

NHL commissioner Gary Bettman, in Pebble Beach, Calif., for a meeting of the league's board of governors, said there is not enough data yet to draw conclusions about any link between concussions and CTE.

"There's no control element because you have to look at everything that went on in a person's life before you can make a judgment as to what a brain may show when you open it up," Bettman said. "I think it's unfortunate that people use tragedies to jump to conclusions that probably at this stage aren't supported."

Even so, the brains of dozens of amateur and professional athletes who engaged in high-impact sports suggest CTE is not an uncommon affliction. Deceased NHLers Bob Probert, Reggie Fleming and Rick Martin all had the condition, brain examinations showed.

"It's obviously very sad what's happened to a few guys in the league," said Columbus Blue Jackets forward Derek Dorsett. "Obviously we've got to create awareness of it and stuff like that, but at the end of the day, I don't think we should take fighting out of the game."

Defenceman Mark Stuart said players will do what they have to do to remain in the NHL.

"This is their job and this is what they love doing," said the Winnipeg Jet. "The violent part of it is unfortunate and the injuries are very, very unfortunate, but it's up to the individual and they're going to do whatever they can to continue to play."

NHL Players' Association executive director Don Fehr said the findings should not be discounted.

"The findings released by Boston University regarding CTE found in Derek Boogaard's brain, and the forthcoming medical journal article, should be seriously considered by everyone associated with the game," Fehr said in a release. "It is certainly important information that we will be discussing with the players."

Boogaard had not played since Dec. 9, 2010, because of fight-related injuries, including a reported concussion.

In a game two weeks before that final on-ice appearance, the New York Ranger had "seen stars," Boogaard's family told the researchers. Twice diagnosed with post-concussion syndrome, he had also spoken of having his "bell rung" at least20 times.

For two years prior to his death, the Saskatchewan-raised enforcer had other problems—drug addiction, emotional instability and problems with impulse control, along with short-term memory problems and disorientation.

That background clouds his case.

"Boogaard's clinical history was complex, so it is unclear as to if or how much CTE contributed to his behaviour, addiction or death," said neurosurgeon Dr. Robert Stern, co-director of the brains study centre at Boston University.

"However, CTE appears to be a progressive disease in some individuals, so even if it was not directly affecting Boogaard's quality of life and overall functioning before he died, it is possible it could have in the future."

Neuropathologist Dr. Ann McKee, director of the brain bank located at the Bedford VA Medical Center, diagnosed Boogaard with mild CTE after finding early signs of the disease in his cerebral cortex—although the damage was more advanced than what she'd seen in the brains of most other athletes of similar age with CTE.

"Unfortunately this finding does not contribute to our knowledge of the risks of normal hockey play for most participants, as very few hockey players engage in as many fights as Boogaard," said study centre co-director Chris Nowinski.

McKee has analyzed the brains of more than 70 deceased athletes. More than 50 had evidence of CTE, including 14 of 15 former NFL players, as well as college and high school football players, other hockey players, pro wrestlers and boxers. Early evidence of CTE was found in individuals as young as 17.

However, the brains of two other young non-NHL professional hockey players studied did not show signs of CTE, Nowinski said.

Tator, whose Toronto Western Hospital also has a centre that examines post-mortem brains, said his research group and others need to study the donated brains of many more athletes before they can nail down the exact connection between repeated head trauma and CTE. Another question they want to answer is why some people develop the disease while others don't.

Still, the discovery that Boogaard's brain contained deposits of a protein called tau, which is known to be related to the development of dementia, "does ratchet up the concern another notch that repeated blows to the head can cause brain degeneration," he said.

"I think of overriding concern is the fact that there was any of this abnormal protein in somebody of that age."

That should be a red flag for any young player, parent or coach who may see the role of designated fighter as a possible entree into the NHL, Tator stressed.

"They are putting themselves at major risks," he said. "So this should be a warning to those who encourage the role of enforcer and those who play the role of enforcer that what you're doing is setting people up—even yourself—for a life of despair, of depression, of memory loss, of movement disorders."